Update install scripts

Don't build NOX and OVS as root.  Also don't nuke kernel src.  Install
newer autoconf needed for OVS install from Deb backports, not src.

util/deb/vm_clean.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+#Brandon Heller (brandonh@stanford.edu)
+#Clean up after VM installation
+
+sudo apt-get clean
+sudo rm -rf /tmp/*
+history -c
+rm ~/.ssh/id_rsa*
+sudo rm ~/.ssh/authorized_keys2
+sudo rm -rf ~/mininet